There is known Patent Literature 1, as a technique for reducing intrusion of a pillar or a side sill into the interior of a vehicle chamber at the time of a side collision of a vehicle. Specifically, in Patent Literature 1, a pillar is configured such that a lower part of the pillar is greatly deformed than an upper part of the pillar at the time of a side collision (see FIG. 12 in Patent Literature 1). In this case, it is known that a load input from a side surface of a side sill on the vehicle outer side is input obliquely upwardly on the vehicle inner side from a corner portion (lower outer corner portion) of the side sill on the vehicle outer side and on the lower side in section.
In view of the above, there is proposed an idea of providing a partition member such as a bulkhead in a side sill. According to this configuration, it is possible to smoothly transmit a load from the lower outer corner portion of the side sill via the partition member. This makes it possible to improve the transmission performance of a side collision load.
Further, there is known Patent Literature 2, as another technique such that a partition member is provided in a side sill as described above. In Patent Literature 2, it is expected to improve the load transmission performance because a ridge is provided in a partition member. However, in Patent Literature 2, the shape of the ridge is not a shape capable of sufficiently improving the load transmission performance. Thus, there is further room for improvement.